1. Field
Some example embodiments relate to electrowetting display devices, methods of driving the same, and/or methods of manufacturing the same.
2. Description of the Related Art
Wetting is a phenomenon of increasing a surface of a boundary between a solid and a liquid when the solid, the liquid, and a gas contact each other. Wetting occurs not only between a solid and a liquid but also between two liquids that are not mixed with each other. In electrowetting, which is a kind of wetting, a contact angle formed between a conductive liquid droplet that comes into contact with a surface of a solid changes according to a voltage applied to the liquid. For example, when no voltage is applied to a droplet placed on an electrode that is coated with a hydrophobic insulating material, a force (interfacial tension) for reducing a contact area between a solid and a liquid to be as small as possible acts to the droplet since the interaction force between liquid molecules is greater than that between the liquid and the solid.
Therefore, the droplet maintains a contact angle with the solid to be greater than 90° according to the respective interfacial tension of the three phases of solid, liquid, and gas, and thus, a round shape of the droplet is maintained. However, when a voltage is applied between the conductive droplet and the electrode that is coated with a hydrophobic insulating material, electrostatic attraction is generated between the droplet and a surface of the solid, and thus, a contact angle of the droplet with the solid is reduced and the droplet spreads out. At this point, the degree of spreading, that is, the contact angle of the droplet, may be controlled by controlling the intensity of the applied voltage.
By using the principle described above, display pixels provided with an electrode coated with an insulating material and filled with oil and electrolyte may be turned on/off by controlling a voltage applied to the electrode.